Pesticide applicator and composition

ABSTRACT

A pesticide applicator has a mounting surface onto which is bonded a solid pesticide composition. The bonding is provided by a cellulosic sheet disposed between the pesticide and the mounting surface avoiding the requirement for surface knurling or fasteners such as are found in previous solid pesticide applicators. A solid pesticide composition is also disclosed comprising a solid carrier, a pesticide and an amount of flour to promote the dispersion of the pesticide into the wax. Previously known chemical surfactants are not required.

FIELD OF THE INVENTION

The present invention is directed to a pesticide applicator andcomposition. More particularly, the present invention is directed to anapplicator for solid pesticides and a solid pesticide composition.

BACKGROUND OF THE INVENTION

Applicators are known for spot application of pesticides to plants.However, many spot applicators are for the application of liquidpesticides and require complicated valve systems to control the flow ofthe liquid.

Recently, there has been a desire to move away from liquid pesticidesfor spot applications and instead to use solid forms of pesticide. Suchpesticides are solid at ambient temperatures and allow the applicationof pesticide directly to the plant, in a controlled amount, whilereducing unwanted spillage onto surrounding foliage or soil.

An applicator for solid pesticide composition is taught in U.S. Pat. No.4,882,874 issued Nov. 28, 1989. The disclosed applicator retains theblock of pesticide in a paper sleeve and requires that knurls or indentsbe formed in the sleeve, or fasteners, such as staples, be insertedthrough the sleeve to engage the block and maintain the block in thesleeve. In use, this form of attachment requires that the applicator bediscarded or reloaded once the block has been reduced to the level ofthe attachment. Thus, much of the pesticide block is wasted. Inaddition, the mechanical arrangement whereby the pesticide is advancedalong the sleeve of the applicator has been found to fail in someinstances. An applicator is required which overcomes these drawbacks.

Solid pesticide compositions are also known. Because of the hydrophobicnature of common solid carrier materials, such as wax, and thehydrophillic nature of many commonly employed pesticides, such as amineherbicide formulations, problems arise in the preparation of the solidpesticide. Since the two phases are naturally immiscible, surfactantsare required to allow the production of a solid form withoutstratification. However, the surfactants, such as fatty amides, maythemselves create adverse side effects. In addition, the cost of thesolid pesticide is increased by the addition of such surfactants.

SUMMARY OF THE INVENTION

An applicator for solid pesticide compositions has been invented and isdescribed herein which does not require engagement of the pesticideblock within the applicator by means of surface indentations, engagingprotrusions or fasteners. In this way, the applicator presents norestriction to the use of the pesticide and the entirety of the blockcan be used before disposal or reloading of the applicator. Theapplicator is assembled by means of a novel wax to surface attachmentinvolving the use of cellulosic material and microcrystalline wax.

Additionally, a solid pesticide formulation has been invented which doesnot require the use of chemical surfactants.

In a broad aspect of the present invention, there is provided a methodfor mounting a wax-based composition containing microcrystalline waxonto a surface of cellulosic material comprising:

providing a surface of cellulosic material;

heating the wax-based composition to a predetermined temperature whichis at least sufficient to melt the wax-based composition;

bringing the cellulosic material into contact with the wax-basedcomposition; and,

allowing the wax-based composition to solidify in contact with thesurface of cellulosic material, wherein the predetermined temperature ofthe wax-based composition is sufficient to raise the temperature of thecellulosic material to a level which is at least sufficient to melt thewax-based composition.

In another broad aspect of the present invention, there is provided apesticide applicator comprising a mounting surface, a block ofpesticide-containing solid carrier and an intermediate layer ofcellulosic material for mounting the pesticide-containing solid carrieronto the mounting surface, wherein the block of pesticide-containingsolid carrier contains microcrystalline wax.

In an alternative embodiment, there is provided a pesticide applicatorcomprising a mounting surface and a block of pesticide-containing solidcarrier, wherein the applicator mounting surface is formed fromcellulosic material and the pesticide-containing solid carrier containsmicrocrystalline wax and is fused directly to the mounting surface.

In an additional aspect of the present invention, there is provided asolid pesticide composition comprising a solid carrier, a pesticide anda plant product able to absorb liquid to form a gel.

DESCRIPTION OF THE INVENTION

The applicator of the present invention is for use with solid carriercomposition such as a solid pesticide composition wherein the pesticideis contained in a block of solid carrier, such as wax. The applicatorcomprises a mounting surface for supporting the block of solid carrier.The block is maintained on the mounting surface by means of a bondformed between the solid carrier and a cellulosic material. The bondingoccurs when the cellulosic material is brought into contact with moltencarrier composition containing microcrystalline wax. The moltencomposition causes the temperature of the cellulosic material to beraised to allow the infiltration of the molten carrier material betweenthe fibres of the cellulosic material. The carrier is then allowed tocool to form a solid pesticide carrier which is bound to the cellulosicmaterial. To form an applicator, the cellulosic material is firmlyattached by any suitable means to the mounting surface of theapplicator, either before or after the bonding step. Alternatively, themounting surface is, itself, formed from cellulosic material. Thisattachment method is useful with all solid carrier compositions whichcontain microcrystalline wax, such as wax-based compositions andpesticide-containing wax-based compositions.

The cellulosic material must be of a suitable fibre density to allow thebinding of solid carrier while being able to bear the stresses whichwill be present from the weight of the attached solid carrier block andthe stresses encountered during use. Preferably, the cellulosic materialis paper or wood.

The cellulosic material, in the form of a thin sheet, can be attached tothe mounting surface by various means such as by permanent adhesives orpressure sensitive adhesives. The preferred thickness of the sheet is0.003" to 0.020".

Alternatively, the cellulosic material may be formed as a rigid plaqueor card which is slotted or snapped into the mounting surface. In thisembodiment, the mounting surface of the applicator is adapted to matewith the card such as by the provision of flanges to form a slot or bythe provision of a corresponding snap arrangement. In this way, reusableapplicators can be made which can be reloaded with a new pesticide blockwhen the original block is expired.

Alternatively, the mounting surface can itself be formed from cellulosicmaterial such as card board or wood which may extend up to attach to orform the remainder of the applicator. Preferably, the cellulosicmaterial is rigid or maintained rigid by the mounting surface so as toprevent concentration of stress at the bond.

Where the cellulosic material is an intermediate layer, infiltration ofthe carrier through the cellulose may hinder later adhesive mounting ofthe cellulose to the mounting surface. Thus, it is preferred that thelayer of cellulosic material be mounted on the mounting surface prior tobinding with the carrier. This, of course, is not a concern where anadhesive is used which can bond to wax-impregnated cellulose or wherethe carrier is applied to the cellulose in such a way that the laterapplication of adhesives to the cellulose will not be affected.

To enhance the usefulness of the applicator a capping means can beprovided which protects the carrier block from damage or contamination.It is to be understood that a variety of capping arrangements are usefulin the present invention. For example, the cap can be attached to theapplicator by snap or threaded attachments. Alternatively, the cap maybe designed to engage directly a portion of the pesticide block orcellulosic material.

Further an extendable handle can be provided on the applicator. Thehandle can either be formed integrally with the mounting surface oralternatively, be detachable from the mounting surface, to allow compactstorage and packaging.

The solid pesticide composition of the present invention comprises asolid carrier, a pesticide and a sufficient quantity of a plant productable to absorb liquids to form a gel. The plant product acts to allowthe dispersion of the pesticide into the wax and maintains the pesticidein suspension in the wax. Starch or flour derived from plant productsare preferred for use in the pesticide composition. The compositioncomprises an effective amount of pesticide and flour in a solid carrier.Preferably, the composition comprises, by weight, 75-90% solid carrier,and 10-25% flour and pesticide in the amount of 0.5 to 5.0% by volume ofthe pesticide composition. Of course, the amount of flour added to thecomposition depends on the amount of pesticide required for thecomposition to have an effective pesticidal action.

These foregoing aspects of the invention, together with other aspectsand advantages thereof, will be more apparent from the followingdescription of the preferred embodiments thereof, taken in conjunctionwith the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, reference may bemade, by way of example, to the following diagrammatic drawings, inwhich:

FIGS. 1A and 1B are sectional views through an applicator of the presentinvention in exploded and assembled form, respectively; and

FIG. 2 is a perspective view of an alternative applicator of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1A and 1B, the pesticide applicator of the presentinvention comprises a body 10 having a mounting surface 12 forsupporting a pesticide-containing block of solid carrier material 14containing microcrystalline wax. Block 14 is maintained on mountingsurface 12 by means of an intermediate layer of cellulosic material 16,such as paper or wood, which is mounted onto the mounting surface andfused to the block.

Cellulosic layer 16 is mounted on mounting surface 12 by means ofadhesives. Preferably, a cyanoacrylate adhesive is used. To enhance themounting of the cellulosic material, the mounting surface is preferablysubstantially planar and the adhesive is applied over the entire surfacewhich will be in contact between the mounting surface and the cellulosicmaterial, to hold the cellulosic material rigidly against the mountingsurface. However, mounting surface 12 can be of any shape and surfaceconfiguration. Block 14 is fused to cellulosic sheet 16 in a manner aswill be described hereinafter.

In the preferred embodiment, the applicator further comprises a handle18. Handle 18 is of a suitable length for use in pesticide applicationand, in this embodiment, is formed to be detachable from body 10. Toprovide detachable mounting to body 10, handle 18 is hollowed at, atleast, its end 20 to engage telescopically a protrusion 22 on body 10.Handle 18 may be mounted onto body 10 in various other ways, such as,for example, by threaded attachment or snapping engagement withoutdeparting from the scope of the present invention.

The applicator of the present embodiment additionally preferablycomprises a capping means 24 to provide protection for block 14 when theapplicator is not in use. Capping means 24 is attached removably to body10 by mating threads 26, 28 or other suitable securing means.Modifications can be made in capping means 24 without departing from thescope of the protection of the present invention.

To assemble the pesticide applicator as shown in FIG. 1B, a novel methodof wax to surface attachment is employed using an intermediate layer ofcellulosic material and microcrystalline wax. Cellulosic material 16 isfirst mounted to mounting surface 12 by means of suitable adhesives. Thesolid carrier containing microcrystalline wax is heated to a suitabletemperature to render the carrier molten. The molten carrier mustadditionally have a sufficient level of heat energy, such that when thecellulosic material is brought into contact with the molten carrier,heat energy is transferred to the cellulose and the temperature of thecellulose is quickly raised to a value above the melting point of thecarrier. In this way, the molten carrier is able to infiltrate thecellulose and surround the fibres of the cellulosic material. Thus, whenthe carrier is allowed to cool, a bond is formed between the celluloseand the carrier that will be as strong as the carrier itself. Themicrocrystalline wax, then acts as an adhesive in the binding of thecarrier to the cellulose.

The temperature of the molten carrier must be raised to a level thatwill allow infiltration of the carrier into the cellulosic material, andit must be understood that the temperature must be sufficiently high toprevent any spontaneous solidification of the carrier when it is broughtinto contact with the cellulosic material. Thus, in the preferredembodiment, the temperature of the molten material is brought to atleast 100° C. At this temperature, when the cellulosic material isbrought into contact with the carrier, the residual water present in thecellulosic material will be raised to the boiling point. Thus, as thecellulose cools a vacuum will be formed which draws the wax into thecellulose. In the preferred embodiment, the molten carrier will becooled in a mould to cause the carrier to solidify in a predeterminedshape, so as to have a carrier block which fits within capping means 24.

While, in the preferred embodiment, the attachment of the cellulosicmaterial to the mounting surface is completed prior to contact with thecarrier, this is not necessary in all embodiments.

Referring to FIG. 2, there is shown an alternate preferred embodiment ofan applicator of the present invention. The applicator of the alternatepreferred embodiment comprises a body 10 having an integral handle 29and a mounting surface 30. Mounting surface 30 preferably comprises acontinuous flange 32 extending about three sides of the periphery ofsurface 30. Flange 32 comprises a return 34 substantially parallel tomounting surface 30. In this way, the mounting surface is provided witha slot to accept and engage a card 36, which in turn supports a block ofpesticide-containing solid carrier 14. In this preferred embodiment,card 36 is formed from cellulosic material, such as wood or card boardand block 14 is fused directly to card 36 by means of the novel carrierto surface attachment method. Alternatively, card 36 can be formed ofother materials such as metals or plastics. When card 36 is formed ofsuch materials, the carrier block is attached to the card by means of anintermediate layer of the cellulosic material as is described withrespect to the embodiment of FIGS. 1A and 1B.

In the alternate preferred embodiment, card 36 is further formed with acentral raised portion 38. Block 14 is fused to this raised portion.Thus, when card 36 is inserted into mounting surface 30, raised portion38 will be substantially flush with, or extend beyond, the return 34. Inthis way all of block 14 is outside return 34 and therefore block 14 isfully accessible for use. In addition, capping means 40 is providedwhich fits over and engages raised portion 38 and provides protectionfor block 14, both during transport of the card/block arrangement andwhen the card is mounted on the applicator.

The embodiment of FIG. 2 provides a reusable applicator body which canbe reloaded with pesticide blocks. This is accomplished simply bysliding out the card 36 with the old pesticide block and sliding in anew card 36 with a fresh block.

Applicators, mentioned above, can be formed of any suitable materialssuch as plastic or metals. Alternatively, the applicator of the presentinvention may be formed entirely of a cellulosic material such as woodor cardboard. Such an applicator allows the direct mounting of thecarrier block onto the mounting surface of the applicator.

The solid pesticide composition of the present invention comprises apesticide, a solid carrier and a sufficient quantity of a plant productwhich is able to absorb liquid to form a gel. The plant product acts toallow the dispersion of the pesticide into the wax and maintains thepesticide in suspension in the wax. Starch or flour derived from plantproducts are preferred. Pesticides useful in the present composition areany of insecticides, bactericides, herbicides or a combination of any ofthe foregoing. For example, CONFRONT™, a water soluble amine availablefrom Dow Chemical Co. can be used in a herbicide composition of thepresent invention. The pesticide is present in the composition in anamount which will vary depending on the specific activity of thepesticide employed.

The solid carrier is solid at ambient temperatures, having a meltingpoint of at least 35° C. Suitable solid carriers are solid soaps,beeswax and mixtures of, by weight, 1-40% paraffin oil and 60-99%paraffin wax; 1-30% microcrystalline wax, 5-40% paraffin oil, and 60-95%paraffin wax. Preferably, the solid carrier comprises at least somemicrocrystalline wax. The presence of such wax increases the meltingpoint of the carrier and increases the adhesive properties of the wax.Thus, preferably the solid carrier comprises 10% microcrystalline wax,15% paraffin oil and 75% paraffin wax.

The flour or starch acts to promote the association of the pesticidewith the wax and to maintain the pesticide in suspension in the wax.Flour derived from plant products is preferred for use in the solidpesticide composition and more preferably, grain flour such as wheatflour is used.

To produce the solid pesticide composition, the solid carrier is firstheated to a temperature above its melting point without increasing thetemperature beyond that of the boiling point of the pesticide to beadded.

While the molten carrier is agitated, as by stirring, the desired amountof flour is added which becomes dispersed in the wax. Agitation ismaintained while the desired amount of liquid pesticide is added.Immediately upon addition of the liquid, the starch and pesticidecombine to form a viscous gel which remains suspended in the wax. Thecomposition is allowed to cool. In this way, the pesticide is dispersedthrough the solidified carrier substantially without stratification.

Preferably, the flour is used in an amount sufficient to allow thedispersion of the pesticide within the carrier. Preferably, flour in anamount of 5-50% by weight of the pesticide composition is employed. Theamount of flour used in the composition can depend on the amount ofpesticide required to be added to the composition for the finalpesticide composition to exhibit effective pesticidal activity.

Preferably, however, a uniform amount of flour is added to the carrierto avoid experimentation to determine the preferred amount of flour tobe added for each amount of pesticide used. Thus, most preferably theflour is added to the solid carrier in amount of about 15-20% by weight.

The following examples show non-limitative formulations, by weight, ofpesticidal compositions according to the present invention and can beused with the presently described inventive pesticide applicator.

    ______________________________________                                        EXAMPLE 1                                                                     Microcrystalline wax                                                                             13.2%                                                      Paraffin wax       52.8%                                                      Paraffin oil       11.0%                                                      Flour              17.0%                                                      CONFRONT           6.0%                                                       EXAMPLE 2                                                                     Microcrystalline wax                                                                             12.5%                                                      Paraffin wax       50.0%                                                      Paraffin oil       7.3%                                                       Flour              17.0%                                                      TURFLON II ™*   13.2%                                                      ______________________________________                                         *TURFLON II is available from DOW Chemicals Co.                          

The Embodiments of the Invention in which an Exclusive Property orPrivilege is claimed are defined as follows:
 1. A pesticide applicatorcomprising a mounting surface, a block of pesticide-containing solidcarrier and an intermediate layer of cellulosic material for mountingthe pesticide-containing solid carrier onto the mounting surface,wherein the block of pesticide-containing solid carrier containsmicrocrystalline wax.
 2. The pesticide applicator of claim 1 furthercomprising an elongated handle formed integral with the mountingsurface.
 3. The pesticide applicator of claim 1 further comprising anelongated handle for attachment to a portion of the mounting surface. 4.The pesticide applicator of claim 1 wherein said layer of cellulosicmaterial comprises a sheet of paper or wood, attached by means ofadhesives to the mounting surface and fused to the pesticide-containingsolid carrier.
 5. The pesticide applicator of claim 1 wherein said layerof cellulosic material comprises a sheet of paper or wood, attached bymeans of mechanical attachments to the mounting surface and fused to thepesticide-containing solid carrier.
 6. The pesticide applicator of claim1 further comprising a capping means, formed to extend removably overthe block of pesticide-containing solid carrier and engage with aportion of the applicator.
 7. The pesticide applicator of claim 1wherein the pesticide-containing solid carrier further comprises a plantproduct which is able to absorb liquid to form a gel.
 8. A pesticideapplicator comprising a mounting surface and a block ofpesticide-containing solid carrier, wherein the applicator mountingsurface is formed from cellulosic material and the pesticide-containingsolid carrier contains microcrystalline wax and is fused directly to themounting surface.